The invention relates to private lines traversing a packet network and re-arrangement of channels among packet network connections.
A traditional telephone exchange configuration provides circuit connections between remote locations. Many of the telecommunications networks currently used are synchronous digital networks. Digitized voice communications are transmitted synchronously over the networks at a fixed rate. Discrete time periods (time slots) can be packed with the digital information for a particular call, and digital information for multiple calls can be packed sequentially to form a time division multiplexed (TDM) data stream.
Private lines, which are dedicated, non-switchable links from one or more customer-specified locations to other customer-specified locations, offer highly available connectivity because they are dedicated to the use of a single entity such as an organization. Private lines can provide a cost-effective alternative to usage-sensitive, switched services.
Traffic from private lines can traverse high-capacity, transmission facilities, including packet-domain network architectures. Asynchronous transfer mode (ATM) networks, for example, use fixed-size packets of data, known as cells, that are transferred between low-overhead packet switches and that provide virtual circuits between the end points of a network. The virtual circuits may be provisioned to provide a permanent virtual circuit between the end points.
One difficulty encountered in providing private line service over a packet network is that the packet network tends to induce additional delays during transmission of the private line traffic. Long delays may be unacceptable and can exacerbate echoes that interfere with the voice or other signals. Although echo cancellation techniques are available, they tend to be costly.